Polar coordinate identities
There’s a few things that we can say are true when working with polar coordinates - identities.
They’re really useful especially later on, when we’ll use them to convert from polar forms to cartesian forms, and the other way round.
We know this because
So
We know this one because
- We can rewrite this one to
if absolutely required.
- We can rearrange this as either of:
We do also need to check which quadrant it is in, to decide on what becomes negative in the polar coordinates.